"use client";

import * as React from "react";
import { AnimatePresence, motion } from "framer-motion";
import { Search, X, Loader2 } from "lucide-react";
import { api, type Suggestions } from "@/lib/api";
import { cn } from "@/lib/utils";

type Item = { kind: "track" | "album" | "artist"; label: string; sub: string; cover: string | null; meta?: string; run: () => void };

export function SearchBar({
  initial,
  busy,
  onSearch,
  onAlbum,
  onArtist,
}: {
  /** Seeds the field from the URL, so a shared link shows what it searched. */
  initial?: string;
  busy?: boolean;
  onSearch: (q: string) => void;
  onAlbum: (id: number) => void;
  onArtist: (id: number) => void;
}) {
  const [q, setQ] = React.useState(initial ?? "");
  const [items, setItems] = React.useState<Item[]>([]);
  const [open, setOpen] = React.useState(false);
  const [sel, setSel] = React.useState(-1);
  const inputRef = React.useRef<HTMLInputElement>(null);
  // A value seeded from the URL must not pop the suggestion list open over the
  // results that link was for. Only typing counts as asking for suggestions.
  const typed = React.useRef(false);
  const seeded = React.useRef(initial);

  // Follows the URL on Back/Forward, but never fights what is being typed:
  // only a genuinely different incoming query replaces the field. Declared
  // after the state it sets, or the effect closes over a binding that is not
  // initialised yet.
  React.useEffect(() => {
    if (initial === undefined || initial === seeded.current) return;
    seeded.current = initial;
    typed.current = false;
    setQ(initial);
    setOpen(false);
  }, [initial]);

  // Debounced so a fast typist makes one upstream call, not eight. The
  // AbortController matters more than the delay: without it a slow response
  // to "rad" can land after "radiohead" and repopulate the stale list.
  React.useEffect(() => {
    const v = q.trim();
    if (v.length < 2) {
      setItems([]);
      setOpen(false);
      return;
    }
    const ac = new AbortController();
    const t = setTimeout(async () => {
      try {
        const d: Suggestions = await api.suggest(v, ac.signal);
        const next: Item[] = [
          ...d.tracks.map((t) => ({
            kind: "track" as const,
            label: t.title,
            sub: t.artist,
            cover: t.cover,
            run: () => {
              const nq = `${t.artist} ${t.title}`;
              setQ(nq);
              setOpen(false);
              onSearch(nq);
            },
          })),
          ...d.albums.map((a) => ({
            kind: "album" as const,
            label: a.title,
            sub: a.artist,
            cover: a.cover,
            meta: a.nb_tracks ? `${a.nb_tracks} tracks` : "",
            run: () => {
              setOpen(false);
              onAlbum(a.album_id);
            },
          })),
          ...d.artists.map((a) => ({
            kind: "artist" as const,
            label: a.name,
            sub: a.nb_album ? `${a.nb_album} releases` : "Artist",
            cover: a.cover,
            run: () => {
              setOpen(false);
              onArtist(a.artist_id);
            },
          })),
        ];
        setItems(next);
        setSel(-1);
        setOpen(typed.current && next.length > 0);
      } catch {
        /* aborted or offline — leave the previous list alone */
      }
    }, 180);
    return () => {
      clearTimeout(t);
      ac.abort();
    };
  }, [q, onSearch, onAlbum, onArtist]);

  // "/" focuses search, the way every music app does.
  React.useEffect(() => {
    const onKey = (e: KeyboardEvent) => {
      const tag = (document.activeElement as HTMLElement)?.tagName;
      if (e.key === "/" && !/^(INPUT|TEXTAREA)$/.test(tag)) {
        e.preventDefault();
        inputRef.current?.focus();
      }
    };
    document.addEventListener("keydown", onKey);
    return () => document.removeEventListener("keydown", onKey);
  }, []);

  const key = (e: React.KeyboardEvent) => {
    if (e.key === "ArrowDown") {
      e.preventDefault();
      setSel((s) => (items.length ? (s + 1) % items.length : -1));
    } else if (e.key === "ArrowUp") {
      e.preventDefault();
      setSel((s) => (items.length ? (s - 1 + items.length) % items.length : -1));
    } else if (e.key === "Escape") {
      setOpen(false);
    } else if (e.key === "Enter") {
      e.preventDefault();
      if (sel >= 0 && items[sel]) items[sel].run();
      else {
        setOpen(false);
        onSearch(q.trim());
      }
    }
  };

  const groups: { title: string; kind: Item["kind"] }[] = [
    { title: "Songs", kind: "track" },
    { title: "Albums", kind: "album" },
    { title: "Artists", kind: "artist" },
  ];

  return (
    <div className="relative z-50">
      <div
        className={cn(
          "card flex items-center gap-3 h-[50px] px-3.5 rounded-[20px]",
          "transition-all duration-250 ease-out",
          "focus-within:border-accent-line focus-within:bg-[var(--surface-2)]",
          "focus-within:shadow-[0_0_0_4px_var(--color-accent-soft)]",
        )}
      >
        <Search className="w-[18px] h-[18px] shrink-0 text-dim" />
        <input
          ref={inputRef}
          type="search"
          value={q}
          onChange={(e) => {
            typed.current = true;
            setQ(e.target.value);
          }}
          onKeyDown={key}
          onFocus={() => items.length && setOpen(true)}
          onBlur={() => setTimeout(() => setOpen(false), 120)}
          placeholder="Search songs, albums, artists…"
          aria-label="Search"
          autoComplete="off"
          spellCheck={false}
          className="flex-1 min-w-0 bg-transparent border-0 outline-none text-base
                     font-medium tracking-[-0.1px] text-ink placeholder:text-dim
                     placeholder:font-normal"
        />
        {busy && <Loader2 className="w-4 h-4 shrink-0 text-accent animate-spin" />}
        {q && !busy && (
          <button
            onClick={() => {
              setQ("");
              inputRef.current?.focus();
            }}
            aria-label="Clear search"
            className="w-6.5 h-6.5 shrink-0 grid place-items-center rounded-full
                       card text-dim hover:text-ink cursor-pointer"
          >
            <X className="w-3.5 h-3.5" />
          </button>
        )}
      </div>

      <AnimatePresence>
        {open && items.length > 0 && (
          <motion.div
            initial={{ opacity: 0, y: -8, scale: 0.985 }}
            animate={{ opacity: 1, y: 0, scale: 1 }}
            exit={{ opacity: 0, y: -8, scale: 0.985 }}
            transition={{ duration: 0.18, ease: [0.22, 0.9, 0.28, 1] }}
            className="sheet absolute top-[calc(100%+8px)] left-0 right-0 z-60 p-1.5
                       rounded-[20px] max-h-[min(64vh,460px)] overflow-y-auto no-scrollbar"
          >
            {groups.map((g) => {
              const rows = items.filter((i) => i.kind === g.kind);
              if (!rows.length) return null;
              return (
                <div key={g.kind}>
                  <div className="px-2.5 pt-2 pb-1 text-caption font-bold uppercase tracking-[0.9px] text-dim">
                    {g.title}
                  </div>
                  {rows.map((it) => {
                    const idx = items.indexOf(it);
                    return (
                      <div
                        key={`${g.kind}-${idx}`}
                        role="option"
                        aria-selected={idx === sel}
                        onMouseDown={(e) => {
                          e.preventDefault();
                          it.run();
                        }}
                        onMouseEnter={() => setSel(idx)}
                        className={cn(
                          "flex items-center gap-3 px-2.5 py-2 rounded-xl cursor-pointer transition-colors",
                          idx === sel && "bg-accent-soft",
                        )}
                      >
                        {/* eslint-disable-next-line @next/next/no-img-element */}
                        <img
                          src={it.cover ?? ""}
                          alt=""
                          loading="lazy"
                          className={cn(
                            "w-[38px] h-[38px] shrink-0 object-cover bg-faint",
                            it.kind === "artist" ? "rounded-full" : "rounded-lg",
                          )}
                          onError={(e) => (e.currentTarget.style.visibility = "hidden")}
                        />
                        <div className="flex-1 min-w-0">
                          <div className="text-sm font-medium clamp1">{it.label}</div>
                          <div className="text-xs text-dim clamp1">{it.sub}</div>
                        </div>
                        {it.meta && <div className="shrink-0 text-caption text-dim">{it.meta}</div>}
                      </div>
                    );
                  })}
                </div>
              );
            })}
          </motion.div>
        )}
      </AnimatePresence>
    </div>
  );
}